Maybe there will be fewer purchases. But only if a few conditions have been met:

• there is an alternative product; and
• buyers can switch to the alternative product; and
• the alternative has characteristics that make it more desirable than the Canadian product once prices rise from tarrifs;

Or

• people can choose to not buy a product at all.

If the Canadian products are still the cheapest (or cheap enough), better enough in some other quality (e.g. not diarrhea inducing?), if buyers are locked into long-term supply agreements, or if people just need the product because there are no alternatives and not buying isn't an option, then tariffs don't impact total sales for those products directly.

It would be interesting to see a breakdown of the tarrifed goods against how elastic the demand for them is.